Alerting systems for vehicle crews



Oct 3, 1967 "r. P. DEMPSEY ETAL 3,345,513

ALERTING SYSTEMS FOR VEHICLE CREWS Filed Oct. 19, 1964 VIM (MM 5P0 em m w V, u M w w m m United States Patent Ofitice ALERTING SYSTEMS FOR VEIHCLE CREWS Terence 1. Dempsey, Coalfalls, Ipswich, Queensland, and Konstantin A. Shkardoon, Riverview, via Ipswich, Queensland, Australia, assignors to The Commissioner for Railways, Brisbane, Queensland, Australia, a corporation of Australia Filed Oct. 19, 1964, Ser. No. 404,866

Claims priority, application Australia, Oct. 21, 1963,

3 Claims. (Cl. 246-182) This invention relates to alerting systems for transport crews, particularly railroad locomotive crews.

A problem with most long-distance transport is the tendency of the driver to doze. This problem has become more acute with diesel and diesel-electric locomotives, where the continuous noise and inactivity are adverse factors.

An object of this invention is to overcome this problem in a way such that there is minimum strain on the crew and no way in which the system can be illegally disabled.

Another object is to provide such a system which is easily fitted to existing vehicles with a minimum of change required.

A further object is to provide a railroad alerting system which may be tied in with known track-safety signalling in certain circumstances.

The alerting system of the invention broadly comprises alerting means for producing an alerting signal at regular predetermined intervals, acknowledgment means operable by the vehicle crew to reset said alarm means to start another said interval, and control means to stop the vehicle at a first predetermined time after the beginning of said alerting signal if said acknowledgment means have not been operated.

Automatic acknowledgment may be provided on actuation of certain of the vehicle controls (cg. throttle or brake).

A particular feature of the invention is that provision is made for operation of said control means if the acknowledgment means remain actuated longer than 'a second predetermined time. This is to prevent illegal 'permanent actuation of the acknowledgment means and to enable the time of permissible actuation to be adjusted independently of the other timing in the system.

In order that the invention may be better understood, an embodiment will now be described by way of example, this embodiment being applicable to diesel-electric locomotives.

In the drawings: 7

FIG. 1 shows a schematic of the electrical system,

FIG. 2 shows part of the schematic of FIG. 1 including modifications, and

FIG. 3 shows a schematic of the pneumatic system used in conjunction with FIG. 1 or FIG. 2.

First indicating generally the function and operation of various features of the circuit with reference to FIG. 1, the system is operated from a power supply 10 through a main switch 11, a system switch 12 and a pressure-operated isolating switch 13.

Four relays are provided as follows:

A/Z actuates its contacts immediately on energization, but allows them to reset only 2 minutes after de-energization. The function of A/2 is to produce an alerting signal by actuating lamp 14 and buzzer 15 on contacts resetting.

M/ 2 actuates its contacts after 90 seconds of energization. Actuation of M/2 contacts sounds the alarm born 16 and applies the brakes by de-energization of B relay.

P/1 actuates its contacts immediately on energiza'tion 3,345,513 Patented Oct. 3, 1967 but allows them'to reset only 20 seconds after de-energization. The function of P/1 is to operate horn 16 and de-ener-gize B, if no acknowledgment is made of alerting signals within 20 seconds.

B is a fail-safe relay which on de-enengization allows the brake pressure to drop in a controlled manner to apply the brakes and stop the train. Drop of brake pressure also releases switch 19 to cut off power to the throttle unit 219 and motor unit 21.

Switches 22, 23, 24 and 25 are operated by pressures in the brake pneumatic circuit as will be later explained.

The time-delays on relays A/2, M/Z and P/1 may be by known devices such as penumatic or hydraulic dashpots or clockwork.

Dealing now with the operation of the alerting system during normal running, a series of parallel switches 17 are provided for acknowledgment of alerting signals from lamp 14 and buzzer 15. Of these 17A may be a button operable by the driver and 17B and 17C may be cam-operated micro switches closed instantaneously by movement of brake and throttle controls respectively. Closure of any one of the switches 17 energises relays A/ 2 and M/ 2, the former through a rectifier 18.

Contacts A1 close, energizing P/ 1, while contacts A2 open, disabling lamp 14- and buzzer 15. If a switch 17 is held down for more than seconds M/Z contacts operate, closing M1 to operate the horn 16 and opening M2 to deener-gize B and thus stop the train.

Horn 16 and its connections constitute an emergency alarm circuit, separate from the alerting circuit comprising buzzer 15 and lamp 14.

If switch 17 is operated normally, being released immediately, relay A/2 starts its two-minute run down at the end of which time, if none of the switches 17 have been again operated, it again actuates lamp 14 and buzzer 15 and de-energizes P/1.

If now no acknowledgment by a switch 17 is made within 20 seconds, P/1 contacts P1 open the circuit to B and stop the train. If acknowledgment is made, P/1 remains energised through A1 and B is not released.

Summarizing the operation so far, an alert signal is given two minutes after the latest acknowledgment (manual or automatic). If no acknowledgment is then received within '20 seconds, the train is stopped. If the manual acknowledgment button 17A is held down (as by being weighted) for more than 90 seconds, the horn 16 blows and the train is stopped.

These arrangements are very suitable for track running conditions, but special arrangements are necessary in stand-over conditions, e.g. when the train is stationary and waiting for a long period.

By raising the brake cylinder pressure to a certain value (say 30 psi.) switch 23 closes, energising A/2 and consequently P/ 1, while switch 25 opens, disconnecting buzzer 15 and horn 16 but not lamp 14. It is to be noted that closure of switch 23 does not energize M/Z since rectifier 18 blocks current through it.

For multiple operation or for towing of a locomotive dead, a brake valve isolating cock is usually closed. This may be utilized in the present system to open switch 13 to cut off all electrical power to the alarm unit, and also to seal off the exhaust passage controlled by relay B in the dead locomotive, thus preventing emergency operation by B.

It is possible that some fault in the air system itself may cause stoppage.

In this case, a lid in the locomotive side may be opened, and an isolating cock within it closed to isolate the brake control from B. This will open switches 19 and 22 and, to prevent disabling the controls, switches 26 and 27 are closed on opening the lid. The isolating cock handle is mechanically situated so that the lid cannot be again closed with the cock closed.

The inner side of the lid is reflectorized so that its open condition is obvious on even cursory inspection. In this condition the alerting functions will still be operative, except for stoppage by relay B.

If a fault in the alerting system itself causes stoppage, switch 12 may be opened to isolate the system. However, switch 12 is sealed and the previous fault procedure must also be carried out to prevent brake application by relay B. The lid of the compartment holding switch 12 is internally reflectorized for positive indication that the seal has been broken.

FIG. 2 shows part of FIG. 1 modified to incorporate a track-operated alerting feature. FIG. 2 omits the circuitry to the left in FIG. 1 and also switches 24, 25, to simplify the description.

FIG. 1 is modified by introducing a magnetic trackoperated switch 30 which when not actuated connects the upper terminal of A2 to the power lead 31 in place of the direct connection of FIG. 1. A second contact P2, operated by relay P/ 2 (replacing P/1 of FIG. 1) is introduced between the lower terminal of A2 and lead 31. The reset coil of receiver 30 is connected in parallel with A/Z.

Receiver 30 comprises 'a pivoted magnetic armature having N and S poles at its ends as indicated. A track transmitter (not shown) consists of a permanent bar magnet with N pole upwards. Receiver 30 is, of course, situated to pass closely above the transmitter. On such passage, the N end is repelled and the S end attracted, thus changing the N and S contacts over. The contacts are held in position by soft-iron pole pieces (not shown) to which the upper end of the armature is attracted. Reset is achieved by energizing coil S, which polarizes the softiron pole to repel the N end and therefore reset 30 to the position shown in FIG. 2. Track receiver and transmitter systems of this kind are known, an example being the British Railways APC/AWS system.

The track-operated alerting feature of FIG. 2 is particularly suitable on single-track lines when approaching a crossing loop, where maximum alertness is necessary. It is of course applicable to other circumstances.

In operation, the system of FIG. 2 acts as before described if receiver 30 is not actuated.

On passing over a track transmitter, contact N on receiver 30 is opened de-energizing relay P/2. Contact P2 is arranged to close immediately (compare contacts P1, which are actuated after 20 seconds delay). Lamp 14 and buzzer 15 give an alert and horn 16 is sounded by closure of contact S, and if no acknowledgment by a switch 17 occurs within 20 seconds, relay B is de-energized to apply the brakes as before. If acknowledgment does occur, reset coil S is energized and receiver 30 reset to the position shown.

The air schematic shown in FIG. 3, shows the usual main air reservoir 101 connected via line 102 to the brake distributing valve 103 and thence to the brake pipe 104.

A line 105 leads through isolating cock 106 (which, as previously described, is situated in the side of the locomotive and interlocked with switches 26 and 27 of FIG. 1) to a penalty application valve 107.

Valve 107 provides means by which air from brake pipe 104 may be exhausted thus causing tram and locomotive brakes to be applied, and is controlled by electropneumatic valve 108 via line 109. The solenoid of valve 108 is relay B (FIGS. 1 and 2). With relay B de-energized line 109 is connected to exhaust line 110 via valve 111 and valve 107 is then open to exhaust 112 and brakes are on. When relay B energizes, valve 108 closes line 109, valve 107 closes and brake pressure appears in brake pipe 104- Valve 111 is connected via line 113 to auto isolating cock 114. When the locomotive is dead or in multiple, cock 114 is always closed and this applies pressure to .1 the underside of valve 111 and causes it to shut olf exhaust line 110.

Therefore, the brakes are released whether relay B is energized or not. At the same time, pressure in pipe 113 operates pneumatic switch 115, which corresponds to switch 13 of FIG. 1, and cuts off the electrical circuit of the alerting system, de-energizing relay B and closing valve 107. Cock 114 is connected to line 104 via the usual auto valve 116.

Normally, when relay B de-energizes, pneumatic switches 117 and 113 (corresponding to switches 19 and 22 of FIG. 1) open immediately. Switch 117 drops ofi throttle power, thus preventing fiashover. Switch 118 opens the alert relay holding circuit for standover, whether switch 23 (FIG. 1) is open or not. Thus, although pneumatic switch 119 (cor-responding to switch 23 in FIG. 1) closes at, say, 30 psi. in the loco brake cylinder 120 during brake application, standover condition does not occur.

If the locomotive is stabled with the electrical alerting system still operative, continuous alert operation would occur. However pneumatic switch 121 (corresponding to switch 24 in FIG. 1) opens with drop of brake cylinder pressure, which occurs due to leakage on stabling. Therefore buzzer 15 and horn 16 are disconnected leaving only lamp 14 to indicate the system is on.

Various changes and modifications may be made to the arrangements described without departing from the invention defined by the claims.

What we claim is:

1. A vehicle crew alerting system comprising a first circuit means for energizing a first relay having contacts which close immediately on energization and which are released a predetermined interval after de-energization; an alerting circuit means actuated on release of said contacts of said first relay; an acknowledgment switch means operable by the driver of said vehicle for energizing said first relay; second circuit means for energizing a second relay having contacts which are released after a predetermined time after de-energization of said second relay; said contacts of said first relay being directly in circuit with a winding of said second relay, said second relay being energized when said contacts are closed; third relay means connected to said first circuit means and energized during closure of said acknowledgment switch, said third relay means having contacts which close after a second predetermined time of continuous energization of said third relay means; and control means to stop said vehicle, said control means being actuated by release of the contacts of said second relay or by closure of the contacts of said third relay means.

2. A system as claimed in claim 1 in which said third relay means is directly connected to said acknowledgment switch and said first relay is connected to said acknowledgment switch through a rectifier; a switch closed when standover conditions occur in said vehicle; and a direct connection from said switch to energize said first relay on closure of said switch.

3. A system as claimed in claim 1, having an emergency alarm circuit separate from said alerting circuit and actuated on closure of contacts both on said third relay and on said second relay.

References Cited EUGENE G. BOTZ, Primary Examiner.

S. B. GREEN, S. T. KRAWCZEWICZ,

Assistant Examiners. 

1. A VEHICLE CREW ALERTING SYSTEM COMPRISING A FIRST CIRCUIT MEANS FOR ENERGIZING A FIRST RELAY HAVING CONTACTS WHICH CLOSE IMMEDIATELY ON ENERGIZATION AND WHICH ARE RELEASED A PREDETERMINED INTERVAL AFTER DE-ENERGIZATION; AN ALERTING CIRCUIT MEANS ACTUATED ON RELEASE OF SAID CONTACTS OF SAID FIRST RELAY; AN ACKNOWLEDGEMENT SWITCH MEANS OPERABLE BY THE DRIVER OF SAID VEHICLE FOR ENERGIZING SAID FIRST RELAY; SECOND CIRCUIT MEANS FOR ENERGIZING A SECOND RELAY HAVING CONTACTS WHICH ARE RELEASED AFTER A PREDETERMINED TIME AFTER DE-ENERGIZATION OF SAID SECOND RELAY; SAID CONTACTS OF SAID FIRST RELAY BEING DIRECTLY IN CIRCUIT WITH A WINDING OF SAID SECOND RELAY, SAID SECOND RELAY BEING ENERGIZED WHEN SAID CONTACTS ARE CLOSED; THIRD RELAY MEANS CONNECTED TO SAID FIRST CIRCUIT MEANS AND ENERGIZED DURING CLOSURE OF SAID ACKNOWLEDGEMENT SWITCH, SAID THIRD RELAY MEANS HAVING CONTACTS WHICH CLOSE AFTER A SECOND PREDETERMINED TIME OF CONTINUOUS ENERGIZATION OF SAID THIRD RELAY MEANS; AND CONTROL MEANS TO STOP SAID VEHICLE, SAID CONTROL MEANS BEING ACTUATED BY RELEASE OF THE CONTACTS OF SAID SECOND RELAY OR BY CLOSURE OF THE CONTACTS OF SAID THIRD RELAY MEANS. 